The multipath, that occurs due to the various objects in the environment between TX and RX, is both a blessing and an impairment for wireless communication. Often it is the multipath, that enables wireless communication when there is no line-of-sight (LoS) between TX and RX, which is the case in overwhelming number of instances of daily communication between people. On the other hand, in the presence of severe multipath, it is a considerably involving task to effectively and reliably detect the desired signal. The relative amplitudes and delays of these multipath components could combine constructively and in some instances destructively, and give rise to a concept known as “fading". The strength and the nature of fading dictate almost every aspect of wireless systems, and is also the basis of the many common definitions of classes of wireless communication systems. [1]}.
